The swelling and adsorption properties of the F44-PTU resin for metal ions Cu2+,Pb2+,Cd2+,Hg2+,Pt4+ and Pd2+ were studied, and the adsorption properties and mechanism for nobel metal ions Pt4+ and Pd2+ were studied es...The swelling and adsorption properties of the F44-PTU resin for metal ions Cu2+,Pb2+,Cd2+,Hg2+,Pt4+ and Pd2+ were studied, and the adsorption properties and mechanism for nobel metal ions Pt4+ and Pd2+ were studied especially. The results showed that the resin had the better adsorption properties for Pt4+ and Pd2+ than other metal ions, and also had bigger adsorption velocity. The adsorption process of the resin for Pt4+ fited the langmuir equation, while the adsorption of the resin for Pd2+ fited the Freundich equation. The process of adsorption of the resin for Pt4+ and Pd2+ were all exothermic.展开更多
A TiO2 modified with PtⅣ chloride was investigated by diffuse reflectance UV-Vis spectra（DRS）,X-ray photoelectron spectroscopy（XPS）, surface photovoltage spectroscopy（SPS） and electric field-induced surface pho...A TiO2 modified with PtⅣ chloride was investigated by diffuse reflectance UV-Vis spectra（DRS）,X-ray photoelectron spectroscopy（XPS）, surface photovoltage spectroscopy（SPS） and electric field-induced surface photovoltage spectroscopy（EFISPS）.XPS showed that a Ti-O-PtⅣClx surface complex between PtⅣ chloride and TiO2 appears to be responsible for visible light absorption.An electron transfer from the surface-complexed PtⅣClx to the conduction band of TiO2 upon absorbing visible light was confirmed by SPS and EFISPS.展开更多
Pt/Pt 4+-TiO2 photocatalyst prepared by a modified sol-gel process was investigated by X-ray diffraction, UV-Vis diffuse reflectance spectra, X-ray photoelectron spectroscopy, time-resolved photoconductivity and terep...Pt/Pt 4+-TiO2 photocatalyst prepared by a modified sol-gel process was investigated by X-ray diffraction, UV-Vis diffuse reflectance spectra, X-ray photoelectron spectroscopy, time-resolved photoconductivity and terephthalic acid fluorescence probing. The photocatalytic activities of catalysts were evaluated by using ethylene oxidation studies under visible light irradiation（λ>450 nm） from 40 to 62 ℃. It is found that the platinum doping in titania caused significant absorption shift to the visible region and the surface recombination of photogenerated carriers was inhibited. The results show that ethylene was not converted on conventional TiO2 while the conversion was 90% and the complete mineralization was achieved over Pt-Pt 4+/TiO2 at 62 ℃ in our experiment. Besides the exponential increase of thermalcatalytic activity, pure photocatalytic activity of the planitized sample enhanced linearly with the increase of temperature.展开更多
Platinum-based bimetallic catalysts have broad applications in polymer electrolyte membrane fuel cells and water splitting. In this work,galvanic displacement reaction was employed to prepare Pt^Ni-P/CNT catalysts usi...Platinum-based bimetallic catalysts have broad applications in polymer electrolyte membrane fuel cells and water splitting. In this work,galvanic displacement reaction was employed to prepare Pt^Ni-P/CNT catalysts using electrolessly-plated Ni-P/CNT. These catalysts were extensively characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Catalytic activities towards methanol oxidation and hydrogen evolution reactions were evaluated and benchmarked with a commercial Pt/C catalyst. Uniform dispersion of Pt on Ni-P particles led to high Pt utilization, and the electrochemical surface area of Pt^Ni-P/CNT with 12.1% Pt loading was found to be 126 m2 gà1, higher than that of a commercial Pt/C(77.9 m2 gà1). The Tafel slopes for the Pt^Ni-P/CNT catalysts were also found to be smaller than that of Pt/C indicating faster kinetics for hydrogen evolution reaction.展开更多
文摘The swelling and adsorption properties of the F44-PTU resin for metal ions Cu2+,Pb2+,Cd2+,Hg2+,Pt4+ and Pd2+ were studied, and the adsorption properties and mechanism for nobel metal ions Pt4+ and Pd2+ were studied especially. The results showed that the resin had the better adsorption properties for Pt4+ and Pd2+ than other metal ions, and also had bigger adsorption velocity. The adsorption process of the resin for Pt4+ fited the langmuir equation, while the adsorption of the resin for Pd2+ fited the Freundich equation. The process of adsorption of the resin for Pt4+ and Pd2+ were all exothermic.
文摘A TiO2 modified with PtⅣ chloride was investigated by diffuse reflectance UV-Vis spectra（DRS）,X-ray photoelectron spectroscopy（XPS）, surface photovoltage spectroscopy（SPS） and electric field-induced surface photovoltage spectroscopy（EFISPS）.XPS showed that a Ti-O-PtⅣClx surface complex between PtⅣ chloride and TiO2 appears to be responsible for visible light absorption.An electron transfer from the surface-complexed PtⅣClx to the conduction band of TiO2 upon absorbing visible light was confirmed by SPS and EFISPS.
文摘Pt/Pt 4+-TiO2 photocatalyst prepared by a modified sol-gel process was investigated by X-ray diffraction, UV-Vis diffuse reflectance spectra, X-ray photoelectron spectroscopy, time-resolved photoconductivity and terephthalic acid fluorescence probing. The photocatalytic activities of catalysts were evaluated by using ethylene oxidation studies under visible light irradiation（λ>450 nm） from 40 to 62 ℃. It is found that the platinum doping in titania caused significant absorption shift to the visible region and the surface recombination of photogenerated carriers was inhibited. The results show that ethylene was not converted on conventional TiO2 while the conversion was 90% and the complete mineralization was achieved over Pt-Pt 4+/TiO2 at 62 ℃ in our experiment. Besides the exponential increase of thermalcatalytic activity, pure photocatalytic activity of the planitized sample enhanced linearly with the increase of temperature.
文摘Platinum-based bimetallic catalysts have broad applications in polymer electrolyte membrane fuel cells and water splitting. In this work,galvanic displacement reaction was employed to prepare Pt^Ni-P/CNT catalysts using electrolessly-plated Ni-P/CNT. These catalysts were extensively characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Catalytic activities towards methanol oxidation and hydrogen evolution reactions were evaluated and benchmarked with a commercial Pt/C catalyst. Uniform dispersion of Pt on Ni-P particles led to high Pt utilization, and the electrochemical surface area of Pt^Ni-P/CNT with 12.1% Pt loading was found to be 126 m2 gà1, higher than that of a commercial Pt/C(77.9 m2 gà1). The Tafel slopes for the Pt^Ni-P/CNT catalysts were also found to be smaller than that of Pt/C indicating faster kinetics for hydrogen evolution reaction.
